A suitable double mattress not only enhances quality of sleep, but also promotes spinal health. The Consumer Council tested 14 models of double mattresses. Based on the firmness measurement, 1 model was graded as “very hard”, 6 as “hard”, and the rest were “medium”. While most mattresses provided good support for back sleepers, performance varied for side sleepers, and inferior models might not provide adequate body support. 8 spring mattress models and 2 foam mattress models scored 4 to 5 points in the back sleeping test, while only 5 (3 spring models and 2 foam models) performed well for side sleeping with a score of 3 to 3.5 points. 3 models exhibited uneven pressure distribution, which could impact comfort, and 1 demonstrated less stability in motion isolation, potentially disturbing a sleeping partner when turning in bed. It is worth noting that the price of a mattress may not correlate with its quality, the price difference between 2 same-type models with the same overall rating of 4 exceeded 2.5 times. The Council advises consumers to conduct sleep trials before purchasing a mattress that suits their own and their partner’s body shape and usual sleeping positions. The Council also found that in case of structural issues, only 5 models offered free repair or replacement services for the entire warranty period. Most of the remaining models offered free repair or replacement only in the first 1 or 2 years upon purchase, after which a proportional fee would be charged. The Council urges traders to proactively explain warranty information at the point of sale, so that consumers fully understand the relevant terms and conditions before making informed choices.
The 14 models of double mattresses tested included 5 pocket spring models, 6 interlocking spring (including Bonnel spring and light spring), and 3 foam models, priced between $2,299 and $9,328. The tests were conducted in independent laboratories in Europe, coordinated by International Consumer Research & Testing (ICRT), using test dummies to simulate medium-sized Asian men and women to evaluate body support performance of the samples in both dorsal (back sleeping) and lateral (side sleeping) positions. The mattresses were also tested for firmness, pressure distribution, point elasticity[1], and moisture permeability. To assess stability, an oscilloscope was used to measure and examine the degree of vibrations upon impact with a heavy test object. In the durability test, the European standard was adopted by running a 140kg roller over the mattress 30,000 times to mimic years of mattress use before examining for signs of wear and tear, changes in firmness, thickness, and support performance. In addition, in accordance with European standards, a smouldering cigarette and a small flame were used to assess flammability resistance.
Overall Back Support Better than Side Support
1 Too Hard to Fit Along Body Curve
Mattresses that are too firm cannot conform to the body’s curves, leading to uneven back support and increased pressure on the body’s support points such as the shoulders and hips. Mattresses that are too soft can cause the spine to bend, and lead to long-term spinal health issues. Of the models tested, 1 was rated as very hard , 6 as hard, and the rest as medium.
A mattress with adequate support allows the whole body to relax while maintaining the spine’s natural curvature when lying on the back. It also allows the spine to remain parallel to the mattress surface while lying on the side. In the back sleeping test, 8 spring mattress models provided good support for both male and female dummies and scored 4 to 5 points. Notably, pocket spring models generally outperformed interlocking spring models, while 2 foam mattress models also showed good support, scoring 4.5 points.
In contrast, most models did not perform as well for the side sleeping test. Only 3 spring models and 2 foam models provided better support for both male and female dummies, scoring 3 to 3.5 points, while most of the rest were not satisfactory and scored only 2.5 points. For some models, the shoulders of the dummies sank into the mattress less than the hips during testing, indicating that these models could not keep the spine parallel to the mattress surface, and might affect the comfort and spinal health of long-term side sleepers. 1 foam model, rated as “very hard”, did not fit the body curves of the dummies, resulting in significant gaps between some parts of the body and the mattress. Consequently, this model provided insufficient support to those areas, leading to poor support performance on both back sleeping and side sleeping positions, and received an overall score of 2.5 points only.
3 Models Showed Uneven Pressure Distribution
Pocket Spring Models Provided Better Stability
Mattresses that do not evenly support different parts of the body could lead to concentrated pressure in certain areas, causing discomfort and pain. 3 models (2 springs and 1 foam) showed uneven pressure distribution. The foam model, in particular, exerted high pressure on the dummies’ hips which not only affects comfort, but may also cause pain in the hips after prolonged sleep, resulting in an overall score of only 2 points.
When sleepers lie on their back, the mattress is subjected to considerable pressure from the hips and shoulders. To provide adequate lumbar support, the section of the mattress between the hips and shoulders should not sink too deeply. 3 spring models had higher point elasticity and provided better lumbar support and scored 4 points, while 1 foam model had low point elasticity thus poorer lumbar support, scoring only 1.5 points.
Moreover, when sharing a bed with a partner, the mattress’s vibration absorption is crucial for preventing disturbance during slumber. 1 pocket spring model had the highest stability with effective vibration absorbing materials and scored 5 points; on the other hand, 1 interlocking spring model was measured with more vibrations in the double-person test mode, which means a person will be more easily affected when the other person turns or moves, showing the worst performance among all models. Overall, pocket spring models generally showed better stability than interlocking spring models. 3 foam models also performed well in the double-person test mode, but among them, 1 had fewer vibrations in the single-person test mode solely due to its low elasticity, which meant that turning or moving on this mattress might require more effort.
Satisfactory Results for Durability Test
4 Models Had High Moisture Permeability
In the durability test, after being subjected to a roller for 30,000 repetitions, all models showed no signs of wear and tear on the mattress material or inside springs or foam, indicating reasonable durability. In the moisture permeability test, 4 models (3 spring models and 1 foam model) performed well with a score of 4.5 to 5 points. Mattress models with good moisture permeability could dissipate moisture effectively and reduce the feeling of stuffiness, making sleeping especially in hot and humid weather more comfortable. 2 spring models had relatively low moisture permeability and scored only 3 points.
In terms of heat dissipation, among the 11 spring models, 4 were classified as “very cold”, 5 as “cold” and 2 as “‘appropriate”; of the 3 foam models, 1 was classified as “cold” and 2 as “appropriate”. Since quilts also affect heat retention or dissipation, consumers should consider their preferences and living habits when selecting a mattress.
As for flammability resistance, all models passed the smoldering cigarette test. However, 1 foam model failed the small flame test. In response to these test results provided by the Council, the Customs and Excise Department (C&ED) pointed out that for ignition resistance of household mattresses, passing the Mainland and internationally adopted smoldering cigarettes test is sufficient. However, the C&ED still encourages traders to improve their products’ fire resistance to meet the small flame test standards.
Repair or Replacement Arrangements Vary
Read Warranty Terms and Conditions Carefully
Mattresses are long-term and relatively expensive durable goods, leading consumers to naturally expect longer and more comprehensive maintenance services. This test revealed that terms and conditions varied significantly among brands, with 1 model even offering no warranty at all. Although the other 13 models come with warranties ranging from 10 to 20 years, only 5 offered full-period free repair or replacement for structural problems caused by quality or production issues, while most of the remaining models only come with free maintenance service for the first 1 to 2 years after purchase, after which repair or replacement will be subject to a specific percentage charge calculated in different ways. As such, consumers are recommended to look into the relevant terms and conditions in advance. Additionally, most traders required a receipt or proof of purchase to enjoy warranty, so it is important for consumers to retain all relevant documents properly.
Consumers should note that warranty provided by manufacturers generally covered structural damage caused by material or production defects, while outer fabric, protective padding, and damage caused by improper use (e.g. folding, bouncing) or mismatch with the bed frame, as well as wear and tear caused from daily use, are usually excluded. In addition, some traders would charge for on-site inspection even within the warranty period, while most others only provided free on-site inspection for the first visit or within the warranty’s first to third years, then charging about $250 to $500 for additional visits. In most cases, transportation costs for repair or replacement would also be borne by consumers.
To protect consumers’ right to information, the Council urges traders to proactively explain to consumers the warranty terms and conditions, calculation of repair costs, on-site inspection fees, transportation fees, and registration requirements, etc. during the sales process. Traders are also urged to provide more convenient mechanisms for warranty registration, such specifying effective date upon purchase without requiring registration, so as to minimise the risk of loss of rights and interest if consumers forget to register. Consumers should also be proactive in seeking information from traders on details of warranty and repairs, and retain relevant documents, including official receipts, in case the need arises.
Making a smart choice in selecting a double mattress and ensuring proper maintenance can improve sleep quality and extend the product lifespan. Consumers can refer to the following tips:
- Choose according to your own and partner’s body shape, sleeping habits and posture. Those who are easily disturbed by their partner’s movements or tend to toss and turn themselves should choose a model with higher stability;
- Conduct sleep trials and comparisons, rather than simply gauging mattress firmness by pressing the surface with hands or sitting on the edge of the bed. When trying out the mattress, wear loose-fitting clothes and mimic usual sleeping positions, such as sleeping on the back and on the side for a while (10 to 15 minutes is recommended) or rolling around a few times, to check how well the mattress fits various body parts such as the lower back and hips, as well as the degree of comfort;
- When choosing a mattress for the elderly, pay attention to edge support and height from the ground (set on a bed frame) to ensure safety and stability when getting in and out of bed. Choose a mattress with better edge support and moderate firmness to prevent slips and injuries while sitting at the bed edge; the height of the mattress (when set on a bed frame) should allow both feet to rest evenly and firmly on the ground, with knees at about 90 degrees, to minimise the risk of falling or difficulty in standing up;
- Don’t forget to remove the mattress’s protective plastic cover before use to maintain moisture and air permeability, and use a washable protector to keep the mattress clean;
- It is recommended to flip the mattress upside down (for double-sided mattresses) and to swap the head and tail every 3 months to restore elasticity at the parts of mattress under prolonged pressure and also to dispel moisture.
[1] Point elasticity was tested by using 2 hemispheres to imitate a body's shoulders and hips being pressed on a mattress. The smaller the difference in height at the middle of the pressure points between exerting and without pressure, the higher the point elasticity of the sample at 2 points of pressure thus the better lumbar support.
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